1. Field of the Invention
This invention relates to a device for applying coating materials, such as, for example, paints, epoxies, polymers, and the like. In particular, the invention relates to a dispensing device or gun for application of liquid materials which must be atomized and delivered in a spray pattern.
The invention is particularly suited for applications which require the liquid coating material to be dispensed and applied evenly, and where merely pouring the liquid compound onto the contact surface does not produce the desired result. In this case, atomization of the fluid stream in order to produce a spray pattern is commonly required.
Atomization of a fluid can be achieved either by pumping the fluid through an orifice at high pressure using an apparatus specifically designed to create atomization, or, alternatively, by air atomization.
2. Description of the Prior Art
Air atomization is a known process, where, as the stream of fluid under low pressure exits the dispensing device, the fluid stream is enveloped by pressurized air delivered to the fluid exit point to form droplets in a defined pattern. It is known in the prior art to attach an air nozzle assembly to the exit point of a delivery tube of a dispensing device in order to achieve air atomization. There are a number of known designs for the air nozzle assembly and for the means of attaching it to the fluid exit point of a dispensing device.
Prior art devices typically deliver the pressurized air to the air nozzle assembly through an air conduit in the form of a flexible hose or tube positioned externally along the entire length of the delivery tube of the dispensing device. The air conduit typically terminates at the air nozzle assembly. Accordingly, the entire apparatus takes up a large amount of space, making the dispensing device cumbersome, awkward to disassemble, and difficult to operate in tight spaces, such as inside a small mold cavity, or in crevices.